Efficiency optimization in a wave energy hyperbaric converter

This paper considers the problem of optimizing the efficiency of the primary conversion on an ocean wave energy hyperbaric converter. This wave energy converter (WEC) is an oscillating-body linked to a hyperbaric chamber. By solving the equation of motion of the power take-off mechanism, it is shown that optimal conditions for improving the absorbed power relate the buoy parameters and the chamber pressure with the incident waves. This work also proposes an algorithm for finding the best time interval that the body remains locked when latching control strategy is used to enhance the efficiency of the WEC. Numerical simulations are presented in order to evaluate the optimum conditions of the hyperbaric WEC and the performance of the proposed algorithm.

[1]  Tor Onshus,et al.  The Norwegian wave-power buoy project , 1982 .

[2]  L. C. Iversen,et al.  Numerical method for computing the power absorbed by a phase-controlled point absorber , 1982 .

[3]  W. Cummins THE IMPULSE RESPONSE FUNCTION AND SHIP MOTIONS , 2010 .

[4]  H. Eidsmoen,et al.  SIMULATION OF A TIGHT-MOORED AMPLITUDE- LIMITED HEAVING-BUOY WAVE-ENERGY CONVERTER WITH PHASE CONTROL , 1998 .

[5]  Martin Greenhow,et al.  Optimal heave motion of some axisymmetric wave energy devices in sinusoidal waves , 1997 .

[6]  J. N. Newman The Exciting Forces on Fixed Bodies in Waves , 1963 .

[7]  Johannes Falnes,et al.  Optimum operation of improved wave-power converter , 1977 .

[8]  J. Falnes Ocean Waves and Oscillating Systems , 2002 .

[9]  Stephen H. Salter Power conversion systems for Ducks , 1979 .

[10]  Segen F. Estefen,et al.  Wave Energy Hyperbaric Device for Electricity Production , 2007 .

[11]  J. Falnes,et al.  A resonant point absorber of ocean-wave power , 1975, Nature.

[12]  A. Belegundu,et al.  Optimization Concepts and Applications in Engineering , 2011 .

[13]  António F.O. Falcão,et al.  Phase control through load control of oscillating-body wave energy converters with hydraulic PTO system , 2008 .

[14]  Aurélien Babarit,et al.  Comparison of latching control strategies for a heaving wave energy device in random sea , 2004 .

[15]  Segen F. Estefen,et al.  Experimental and Numerical Studies of the Wave Energy Hyberbaric Device for Electricity Production , 2008 .

[16]  U. Korde Efficient primary energy conversion in irregular waves , 1999 .

[17]  Paula B. Garcia-Rosa,et al.  Turbine speed control for an ocean wave energy conversion system , 2009, 2009 American Control Conference.

[18]  António Sarmento,et al.  Overall-efficiency optimisation in OWC devices , 2003 .

[19]  D. Evans A theory for wave-power absorption by oscillating bodies , 1976, Journal of Fluid Mechanics.

[20]  Charles M Close,et al.  The analysis of linear circuits , 1966 .

[21]  A. Clément,et al.  Optimal Latching Control of a Wave Energy Device in Regular and Irregular Waves , 2006 .

[22]  A. Clément,et al.  Wave energy in Europe: current status and perspectives , 2002 .